Question

2^2n＋1等于7,2^2＋m等于5,求2^3n-m等于?

Answer 1

2^2n?表示2的2n次方?

解得（6√6 ）-1

2^2n+1?表示2的2n+1次方?

2^2n＋1=7推出2^n*2^n*2=7即2^n=√(7/2)

2^2+m=5推出4*2^m=5即　2^m=5/4

所以2^3n-m=(2^n)^3/2^m

=[√(7/2)]^3/(5/4)

=(7/5)*√14